First, Britain’s parliament voted against Prime Minister David Cameron’s plans to join any military action (initiated by the United States) against Syria. Now Germany has followed suit. Among America’s best friends, only France has signaled that it will support President Obama if he decides to punish Bashar al-Assad for his use of chemical weapons.

But the British and the Germans aren’t alone. A new NBC poll shows that 52 percent of Americans oppose any plans for the United States to intervene militarily in the Syrian conflict. It also shows Obama’s ratings on his management of foreign policy have tumbled.

What all the dissenters may fear is the accidental outbreak of a third world war. And, given the nature of the political and religious rivalries in the Middle East, and our nation’s genuine interest in protecting those nations in the region that are essential to preserving Israel’s existence, a much wider war is not an entirely unreasonable concept.

The chemical attack in the Damascus suburbs on Aug. 21 is widely believed to have been carried out by Syrian government forces and “must not go unpunished,” French President Francois Hollande told Le Monde, a French daily newspaper. “Otherwise, it would be taking the risk of an escalation that would normalize the use of these weapons and threaten other countries.”

Hollande said a military strike against Syria would have a “dissuasion value” and help persuade Assad to seek a negotiated “political solution” to the conflict. That, of course, would be the ideal solution to the vexing problem facing Obama and those who support him, but Assad has shown no tendencies to embrace what more reasonable people call common sense.

And speaking of common sense, in London and Berlin there are long memories of what the politicians (and their voters) regard as the tragic miscalculation about Iraq. The British people especially remain furious that their then-prime minister, Tony Blair, stood with President George W. Bush on the issue of whether Saddam Hussein had weapons of mass destruction.

Blair’s popularity plunged when the truth about Iraq emerged.

And the truth is the evidence put forward by America’s vaunted intelligence services was driven more by politics than facts. The British and Germans want no part of any similar debacle, even though they both roundly condemn Assad’s behavior. And apparently the American public, to a large degree, shares their skepticism.

Even so, there’s every indication that Obama plans to do something, and to do it very soon, to demonstrate that the United States was serious when the president warned Assad not to cross the “red line” that the use of chemical weapons would represent.

The military action, whatever its nature, would also send a strong signal to Iran and to those Arab groups that believe America is all talk and no action.

“The kind of attack the administration appears to be planning will demonstrate to Syria and to others that there is a cost the United States is willing to impose for crossing clearly established American red lines and violating widely held international norms,” Richard Fontaine, the president of the Center for a New American Security, a centrist research center, told The New York Times.

But he also offered this note of caution: “It probably will do very little to alter the fundamental balance of forces on the ground or hasten the end of the conflict.”

And there’s the rub. If an expert such as Fontaine sees that outcome of a military strike by the United States, it shouldn’t surprise anyone that there are as many doubters as supporters.